Effect of <i>Sanyinjiao</i> (Spleen-6) Acupoint for Pain Management in Primary Dysmenorrhea: An Updated Systematic Review and Meta-Analysis.

Abstract

<h4>Objectives</h4>Available literature highlights the effectiveness of Acupuncture or Acupressure on the Spleen 6 acupoint (<i>Sanyinjiao</i> or SP-6) for pain management in primary dysmenorrhea (PD). The objective of the current systematic review and meta-analysis is to provide an updated assessment of available randomized and non-randomized controlled trials and to compare the effectiveness of acupressure and acupuncture stimulation of <i>Sanyinjiao</i> among patients with PD.<h4>Methods</h4>We conducted a comprehensive literature search on various electronic databases including Embase, PubMed, and the Cochrane Library from January 1990 to March 2023 to identify the comparative studies (randomized and non-randomized controlled trials) that assessed the effects of acupressure or acupuncture on the <i>Sanyinjiao</i> acupoint in patients with PD. We assessed the studies' risk of bias in accordance with the Cochrane Handbook for Systematic Reviews of Interventions, and certainty of evidence using the Grading of Recommendations Assessment. Subsequently, a fixed-effects meta-analysis was performed using the Der-Simonian and Laird method to combine intervention effects from the included studies. The primary outcome of interest was a reduction in pain.<h4>Results</h4>We included 19 studies (9 acupressure and 10 acupuncture) with 1171 PD patients. This meta-analysis showed a significant (Standardized Mean Difference, SMD: -0.29, 95% confidence interval -0.41 to -0.17, <i>p</i> < 0.001) reduction in pain, for both acupressure and acupuncture at <i>Sanyinjiao</i> acupoint with considerable heterogeneity. Acupressure was found to be more effective than acupuncture stimulation in reducing pain associated with PD (SMD: -0.52, 95% confidence interval -0.71 to -0.33, <i>p</i> < 0.001).<h4>Conclusion</h4>The findings of this updated systematic review and meta-analysis suggest that both acupuncture and acupressure on <i>Sanyinjiao</i> acupoint could effectively reduce pain associated with PD. Acupressure stimulation, in particular, was found to be more effective than acupuncture stimulation of the acupoint in reducing pain associated with PD.